1. Field of the Invention
The present invention relates to a display system and more particularly to a display system including a first display device for storing screen data and a second display device for displaying a screen based on the screen data stored by the first display device.
2. Description of the Related Art
In recent years, portable communication terminals have been more and more sophisticated, and people own portable communication terminals in place of PCs (Personal Computers). Portable communication terminals allow documents in electronic form to be viewed and edited at any place. Portable communication terminals are used in various business and daily life situations.
With sophistication of portable communication terminals, cooperation between an image forming apparatus and a portable communication terminal has been requested in a display system including an image forming apparatus having a main unit panel (operation panel) and a portable communication terminal having a remote panel. Specifically, it is requested that, for example, the same screen as the screen displayed on the main unit panel be displayed on the remote panel as well.
When the same screen as the screen on a main unit panel is displayed on a remote panel, conventionally, a portable communication terminal acquires screen data to be displayed on a main unit panel that is stored, for example, in a RAM (Random Access Memory) of an image forming apparatus, and displays a screen on a remote panel based on the acquired screen data. When an operation of changing a still image screen displayed on the remote panel is accepted from the user, data of the changed screen is acquired from the image forming apparatus every time a change is made.
The technique of displaying a screen of a display source at another terminal is disclosed, for example, in Document 1 below. Document 1 discloses a communication apparatus including a storage unit for storing performance of a transmission-destination device and a moving image generation unit for generating moving images by morphing. This communication apparatus determines the number of images to be generated by morphing and the data quantity for each image in accordance with the performance of the transmission-destination device. The communication apparatus determines the number of images and the data quantity in accordance with a receiving speed of the transmission-destination device.    Document 1: Japanese Laid-Open Patent Publication No. 2005-135047
Some portable communication terminals can accept operation by gesture, such as flick operation. In the portable communication terminals of this type, more direct and more intuitive operation is possible. However, with the conventional technique, when flick operation is performed at a portable communication terminal, an image forming apparatus cannot handle the flick operation, and the portable communication terminal thus cannot display a screen as desired by the user. This is inconvenient for users.
This is not only the problem between an image forming apparatus and a portable communication terminal and is a common problem to a display system including a first display device for storing screen data and a second display device for displaying a screen based on the screen data stored by the first display device.